Training current employees can be costly — depending on the avenue you take. You can go the expensive route of paying for classes or cost-effective ones like learning lunches. But often, managers forget how improtant professional development is for employees. And that's actually one of the top reasons why people look for opportunities elsewhere.

To put things into perspective, Mindflash put together this infographic that compares the cost of training current employees versus hiring new ones.

(Click to enlarge)

Want to improve employee retention? There you've got it — leverage training and development in your organization as a way to keep people sticking around longer.